Dry matter recovery, ensiling characteristics and aerobic stability of oat silage treated with microbial inoculants at different temperatures

ABSTRACT

To evaluate the effects of temperature and lactic acid bacteria (LAB) inoculants on oat silage in Loess Plateau of China, oat was harvested at dough stage, inoculated without (Control) or with LAB inoculants Synlac I (SLI, Lactobacillus plantarum and Pedioccocus acidilactici) and a selected strain HT1 (L. rhamnosus) and ensiled at 25°C (T25), 35°C (T35) and 45°C (T45). The fermentation quality was measured after 60 d of ensiling and the aerobic exposure was conducted at 30°C for 9 d. The results showed that control silage (stored at 25°C) had better fermentation quality than that ensiled at 35°C or 45°C. High temperature of 45°C resulted in sharp decreases in LAB counts and lactic acid concentration and increases in pH and NH₃-N concentration in the control group. Inoculation improved the fermentation quality, and HT1 was more effective than SLI at 35°C and 45°C, while SLI showed better performance at 25°C. All silages displayed mild fluctuation for all treatments at the first 3 d of aerobic exposure, and significant differences were observed among treatments after that. Both control and inoculated silages stored at 25°C showed a sharp pH increase, while HT1 treated silages stored at 35°C and 45°C maintained stable pH and better fermentation quality during the aerobic exposure. In conclusion, SLI was suitable for oat silage fermentation at normal atmospheric temperature (25°C), while HT1 was more effective in improving DM recovery, fermentation quality and aerobic stability of oat silage at high temperature during summer in the Loess Plateau of China.

KEYWORDS:

• Oat silage
• lactic acid bacteria
• temperature
• ensiling characteristics
• aerobic exposure

Acknowledgments

The authors gratefully acknowledge Department of Grassland Science, South China Agricultural University, Guangzhou, China, for supplying the silage fermentation additive (HT1) evaluated in this research.

Author contribution

Jikuan Chai: Conceptualisation (equal); data curation (lead); writing – original draft preparation (lead); writing – review and editing (equal). Wenlong Gong: Methodology (equal); investigation (equal); data curation (supporting). Jie Bai: Investigation (equal). Zeliang Ju: Investigation (equal). Guiqin Zhao: Conceptualisation (lead); methodology (equal); writing – review and editing (equal); project administration (lead); funding acquisition (lead).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under Grant [NSFC 32160810]; China Agriculture Research System under Grant [CARS-07]